The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 14, 1987
Filed:
Aug. 19, 1985
Applicant:
Inventors:
Toshiaki Okuyama, Ibaraki, JP;
Takayuki Matsui, Hitachi, JP;
Noboru Fujimoto, Hitachi, JP;
Yuzuru Kubota, Hitachi, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H02P / ;
U.S. Cl.
CPC ...
318802 ; 318805 ; 318808 ;
Abstract
In induction motor driven by a voltage-type inverter, the torque current component is determined by detecting a primary current flowing to the induction motor. On the basis of the torque current component determined, the output voltage and frequency of the voltage-type inverter are controlled. Additionally, the rotational speed of the induction motor is estimated on the basis of the detected torque current component and the speed of the induction motor is controlled such that the estimated speed signal coincides with a speed command signal.